Allow creation of ATMOS sync on channel 14.atmos

1 files changed, 163 insertions, 0 deletions

diff --git a/test/sync_test.cc b/test/sync_test.cc
new file mode 100644
index 00000000..ff3adf1f
--- /dev/null
+++ b/test/sync_test.cc
@@ -0,0 +1,163 @@
+/*
+    Copyright (C) 2020 Carl Hetherington <cth@carlh.net>
+
+    This file is part of libdcp.
+
+    libdcp is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    libdcp is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with libdcp.  If not, see <http://www.gnu.org/licenses/>.
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of portions of this program with the
+    OpenSSL library under certain conditions as described in each
+    individual source file, and distribute linked combinations
+    including the two.
+
+    You must obey the GNU General Public License in all respects
+    for all of the code used other than OpenSSL.  If you modify
+    file(s) with this exception, you may extend this exception to your
+    version of the file(s), but you are not obligated to do so.  If you
+    do not wish to do so, delete this exception statement from your
+    version.  If you delete this exception statement from all source
+    files in the program, then also delete it here.
+*/
+
+
+#include "sound_asset.h"
+#include "sound_asset_reader.h"
+#include "sound_asset_writer.h"
+#include "test.h"
+#include <boost/filesystem.hpp>
+#include <boost/shared_ptr.hpp>
+#include <boost/test/unit_test.hpp>
+#include <vector>
+
+
+using std::vector;
+using boost::shared_array;
+using boost::shared_ptr;
+
+
+static const int sample_A = 0.038 * 8388608;
+static const int sample_B = 0.092 * 8388608;
+static const int sample_C = 0.071 * 8388608;
+
+static
+bool
+close (int reference, int sample)
+{
+	return abs (reference - sample) < 4096;
+}
+
+
+static
+bool
+close (int ref1, int ref2, int ref3, int ref4, int check[4])
+{
+	return close(ref1, check[0]) && close(ref2, check[1]) && close(ref3, check[2]) && close(ref4, check[3]);
+}
+
+
+static int const sync_channel = 13;
+static int const bytes_per_sample = 3;
+
+
+static int
+read_sync_sample (uint8_t const* data, int sample_index, int channels)
+{
+	uint8_t const* p = data + (sample_index * channels * bytes_per_sample) + sync_channel * bytes_per_sample;
+	return static_cast<int>((p[0] << 8) | (p[1] << 16) | (p[2] << 24)) / 256;
+}
+
+
+BOOST_AUTO_TEST_CASE (sync_test1)
+{
+	dcp::SoundAsset asset (private_test / "atmos_pcm.mxf");
+	shared_ptr<dcp::SoundAssetReader> reader = asset.start_read ();
+	shared_ptr<const dcp::SoundFrame> frame = reader->get_frame (0);
+
+	/* Read the samples from the first MXF frame of channel 14 and decode them to bits */
+	uint8_t const * data = frame->data ();
+	vector<bool> ref;
+	/* There's 2000 samples which contain 500 bits of data */
+	for (int i = 0; i < 500; ++i) {
+		int bit[4];
+		for (int j = 0; j < 4; ++j) {
+			int sample_index = i * 4 + j;
+			bit[j] = read_sync_sample (data, sample_index, asset.channels());
+		}
+
+		if (close(sample_A, sample_B, sample_B, sample_A, bit)) {
+			ref.push_back (false);
+		} else if (close(-sample_A, -sample_B, -sample_B, -sample_A, bit)) {
+			ref.push_back (false);
+		} else if (close(sample_C, sample_C, -sample_C, -sample_C, bit)) {
+			ref.push_back (true);
+		} else if (close(-sample_C, -sample_C, sample_C, sample_C, bit)) {
+			ref.push_back (true);
+		} else {
+			BOOST_CHECK (false);
+		}
+	}
+
+	shared_ptr<dcp::SoundAssetWriter> writer = asset.start_write ("build/test/foo.mxf", true);
+
+	/* Compare the sync bits made by SoundAssetWriter to the "proper" ones in the MXF */
+	BOOST_CHECK (ref == writer->create_sync_packets());
+}
+
+
+BOOST_AUTO_TEST_CASE (sync_test2)
+{
+	/* Make a MXF with the same ID as atmos_pcm.mxf and write a frame of random stuff */
+	int const channels = 14;
+	dcp::SoundAsset asset (dcp::Fraction(24, 1), 48000, channels, dcp::SMPTE);
+	asset._id = "e004046e09234f90a4ae4355e7e83506";
+	boost::system::error_code ec;
+	boost::filesystem::remove ("build/test/foo.mxf", ec);
+	shared_ptr<dcp::SoundAssetWriter> writer = asset.start_write ("build/test/foo.mxf", true);
+
+	int const frames = 2000;
+	float** junk = new float*[channels];
+	for (int i = 0; i < channels; ++i) {
+		junk[i] = new float[frames];
+		for (int j = 0; j < frames; ++j) {
+			junk[i][j] = float(rand()) / RAND_MAX;
+		}
+	}
+
+	writer->write (junk, frames);
+	for (int i = 0; i < channels; ++i) {
+		delete[] junk[i];
+	}
+	delete[] junk;
+	writer->finalize ();
+
+	/* Check that channel 14 on the first frame matches channel 14 on the reference */
+	dcp::SoundAsset ref (private_test / "atmos_pcm.mxf");
+	dcp::SoundAsset check ("build/test/foo.mxf");
+
+	shared_ptr<dcp::SoundAssetReader> ref_read = ref.start_read ();
+	shared_ptr<dcp::SoundAssetReader> check_read = check.start_read ();
+
+	shared_ptr<const dcp::SoundFrame> ref_frame = ref_read->get_frame(0);
+	uint8_t const* ref_data = ref_frame->data();
+	shared_ptr<const dcp::SoundFrame> check_frame = check_read->get_frame(0);
+	uint8_t const* check_data = check_frame->data();
+
+	for (int i = 0; i < frames; ++i) {
+		int ref_sample = read_sync_sample (ref_data, i, ref.channels());
+		int check_sample = read_sync_sample (check_data, i, check.channels());
+		BOOST_CHECK (abs(ref_sample - check_sample) < 2);
+	}
+}
+